package com.yjck.ijpay.utils.wxutils;

import org.apache.commons.lang3.StringUtils;

import java.security.MessageDigest;

public class MD5 {

	private static final String hexDigits[] = { "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", "a", "b", "c", "d",
			"e", "f" };

	public static String md5(String str) {
		try {
			MessageDigest md = MessageDigest.getInstance("MD5");
			md.update(str.getBytes());
			byte b[] = md.digest();

			int i;

			StringBuffer buf = new StringBuffer("");
			for (int offset = 0; offset < b.length; offset++) {
				i = b[offset];
				if (i < 0)
					i += 256;
				if (i < 16)
					buf.append("0");
				buf.append(Integer.toHexString(i));
			}
			str = buf.toString();
		} catch (Exception e) {
			e.printStackTrace();

		}
		return str;
	}

	public static String MD5Encode(String origin, String charsetname) {
		String resultString = null;
		try {
			resultString = new String(origin);
			MessageDigest md = MessageDigest.getInstance("MD5");
			if (StringUtils.isEmpty(charsetname)) {
				resultString = byteArrayToHexString(md.digest(resultString.getBytes("utf-8")));
			} else {
				resultString = byteArrayToHexString(md.digest(resultString.getBytes(charsetname)));
			}
		} catch (Exception exception) {

		}
		return resultString;
	}

	private static String byteToHexString(byte b) {
		int n = b;
		if (n < 0)
			n += 256;
		int d1 = n / 16;
		int d2 = n % 16;
		return hexDigits[d1] + hexDigits[d2];
	}

	private static String byteArrayToHexString(byte b[]) {
		StringBuffer buffer = new StringBuffer();
		for (int i = 0; i < b.length; i++)
			buffer.append(byteToHexString(b[i]));
		return buffer.toString();
	}

	public static void main(String[] args) {
		System.out.println(md5("31119@qq.com" + "123456"));
		System.out.println(md5("mj1"));
	}

	/**
	 * 验证字符串是否匹配
	 * 
	 * @param unknown
	 *            待验证的字符串
	 * @param okHex
	 *            使用MD5加密过的16进制字符串
	 * @return 匹配返回true，不匹配返回false
	 */
	// public static boolean validate(String unknown , String okHex) {
	// return okHex.equals(md5(unknown));
	// }

}
